There are a few guidelines that you can follow to maintain your computer and keep it running smoothly.

This article discusses how to use the tools available in Windows XP Service Pack 2 (SP2) to more efficiently maintain your computer and safeguard your privacy when you're online.

On This Page
Free Up Disk Space
Speed Up Access to Data
Detect and Repair Disk Errors
Protect Your Computer Against Spyware

Free Up Disk Space
By freeing disk space, you can improve the performance of your computer. The Disk Cleanup tool helps you free up space on your hard disk. The utility identifies files that you can safely delete, and then enables you to choose whether you want to delete some or all of the identified files.

Use Disk Cleanup to:

• Remove temporary Internet files.

• Remove downloaded program files (such as Microsoft ActiveX controls and Java applets).

• Empty the Recycle Bin.

• Remove Windows temporary files.

• Remove optional Windows components that you don't use.

• Remove installed programs that you no longer use.


Tip: Typically, temporary Internet files take the most amount of space because the browser caches each page you visit for faster access later.

To use Disk Cleanup

1.
Click Start, point to All Programs, point to Accessories, point to System Tools, and then click Disk Cleanup. If several drives are available, you might be prompted to specify which drive you want to clean.



Disk Cleanup calculates the amount of space you will be able to free.


2.
In the Disk Cleanup for dialog box, scroll through the ******* of the Files to delete list.



Choose the files that you want to delete.


3.
Clear the check boxes for files that you don't want to delete, and then click OK.

4.
When prompted to confirm that you want to delete the specified files, click Yes.


After a few minutes, the process completes and the Disk Cleanup dialog box closes, leaving your computer cleaner and performing better.

this is the link:
http://www.microsoft.com/atwork/getstarted/speed.mspx